Voltage converters are used to provide stable supply voltages to a large variety of electronic products. In switching voltage converters, voltage can be up-converted and/or down-converted by switching high-side and low-side switches; and the switched voltage can be passed through a low pass filter network for averaging. The filtered voltage is then the output voltage of the converter. Typically, while such switching can provide efficient voltage conversion, the switching also manifests ripple on the output voltage. For example, the switched voltage causes current to flow through a filtering inductor, resulting in an inductor current that includes a ripple current riding on a load current. When the inductor current flows through a load of the filtering network, the voltage across the load (the output voltage of the regulator) similarly manifests a ripple voltage riding on the load voltage.
Some applications seek to minimize, or even eliminate, the ripple voltage. Some conventional approaches tend to use feedback to compare the output voltage with a stable, constant reference voltage. For example, the output voltage can be coupled with the output of a low-dropout (LDO) regulator and with one of its inputs, while the other input of the LDO regulator can be coupled with a stable reference voltage. Such a feedback loop can effectively regulate the ripple out of the output voltage, but such approaches have various limitations.